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GaN-based Class D power amps

The use of GaN-based power transistor tech is now emerging for Class D audio power amplifiers. Seems appropriate to devote a forum thread to this topic. At least 3 companies have commercial class D amps in their books:

Merrill Audio, with their model Element 118 ($36k per monoblock, 400 W into 8 ohms, 800W into 4 ohms), Element 116 ($22k per monoblock, 300 W into 8 ohms, 600W into 4 ohms) and Element 114 (coming soon). 
https://merrillaudio.net

Review of Element 118 at this link:
http://www.enjoythemusic.com/superioraudio/equipment/1018/Merrill_Audio_Element_118_Monoblock_Amplif...

ADG Productions, with their Vivace Class D amp ($15k per monoblock pair, 100W into 4 ohms). (The designer emailed me indicating he has another product in the pipeline.)
http://agdproduction.com
Review of the Vivace Class D moniblocks at this link (warning: link might not work (1/11/2019)):
https://positive-feedback.com/reviews/hardware-reviews/agd-production-vivace-gantube-monoblock-ampli...

Technics SE-R1 Class D stereo amp ($17k per stereo amp, 150WPC into 8 ohms, 300WPC into 4 ohms) 
https://www.technics.com/us/products/r1/se-r1.html
Preliminary review of the Technics SE-R1 at this link:
https://www.stereophile.com/content/technics-se-r1-digital-amplifier
Technics also has a lower priced GaN-based class D integrated amp in their catalog:
https://www.technics.com/us/products/grand-class/stereo-integrated-amplifier-su-g700.html

Anyone listened to or own any of these amps?


celander
ketchup
459 posts
 
The new Nord price is pounds, not USDr
Even worse!
from what I've studied such amps benefit greatly from module isolation
Meaning, the expensive chassis is much more than a pretty face

It still doesn't justify the cost.  I'm a machinist/fabricator, so I know what it takes.  I would rather build my own.  These amps are so simple, even with "module  with so few parts in them.  The costs just don't make sense. 

celander's avatar
celander OP
1,036 posts
 
Peter Lyngdorf got back to me via FB messenger today. He confirmed that his new amp he raved about on his FB page has no GaN-FET tech in it.
celander's avatar
celander OP
1,036 posts
 
+1, Ralph. I suspect the confusion stems from the digital inputs in some of these amps. Folks might forget one needs a DAC circuit to generate the audio signal prior to amplification via an analog stage.
jonnie22
10 posts
 
No DAC needed for the amps I mentioned. Digital-in, w/o converters, meaning a digitally-amplified signal.

How else do these power a signal ?

No-one here should listen Ralph Karsten. He knows tubed circuits and that’s about it...
ricevs
190 posts
 
Actually, the first "digital amp" was the TACT. They do not have an DAC in it. They convert the PCM signal directly to PWM. There is no analog signal ever inside a TACT (except that which is generated via PWM and outputted via the speaker outs). In their white paper they stated that this PCM to PWM conversion was "non linear" by nature and that is why they spent so much time to get it right (make it linear). Most of todays "digital amps" are using this technology. They do not have a DAC inside......they convert PCM directly to PWM. This is why I call them digital amps and why most do. Yes, the output stage is a class D circuit.
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